This invention relates to improvements in a lubricating oil supplying system for an internal combustion engine, arranged to supply lubricating oil to various sliding sections, a variable valve actuation mechanism or the like in the internal combustion engine under the action of an oil pump driven by the internal combustion engine and an electric pump driven by an electric motor.
Hitherto, various types of the lubricating oil supplying systems were proposed and put into practical use. One of such lubricating oil supplying apparatuses is disclosed in a Japanese Patent Provisional Publication No. 2003-148120. Briefly, this lubricating oil supplying system includes a variable valve actuation mechanism serving as a driving device, disposed to the main body of an internal combustion engine. The variable valve actuation mechanism and various sliding sections are supplied with lubricating oil stored in a lubricating oil tank. The lubricating oil stored within the lubricating oil tank is sucked and supplied to the main body of the internal combustion engine, under the action of a driven pump driven by the internal combustion engine.
The lubricating oil supplying system further includes a heat accumulative container which is in communication with the discharge side of the driven pump and stores therein the lubricating oil discharged from the driven pump, warming the lubricating oil. The lubricating oil within the heat accumulative container is sucked and supplied to the variable valve actuation mechanism under the action of an electric pump disposed separate from the driven pump. Consequently, the electric pump and various opening-closing valves are driven through a control means in accordance with a prediction result of a starting prediction means for the internal combustion engine, thereby supplying the lubricating oil, which has been previously heated before the starting of the internal combustion engine, to the variable valve actuation mechanism so as to improve a driving response of the engine.